From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: from minnie.tuhs.org (minnie.tuhs.org [IPv6:2600:3c01:e000:146::1]) by inbox.vuxu.org (Postfix) with ESMTP id 86F192463E for ; Fri, 5 Jul 2024 23:49:14 +0200 (CEST) Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id B8AAB43DC1; Sat, 6 Jul 2024 07:49:09 +1000 (AEST) Received: from mcvoy.com (mcvoy.com [192.169.23.250]) by minnie.tuhs.org (Postfix) with ESMTPS id 1A1BA43DC0 for ; Sat, 6 Jul 2024 07:49:02 +1000 (AEST) Received: by mcvoy.com (Postfix, from userid 3546) id 749F335E9ED; Fri, 5 Jul 2024 14:49:01 -0700 (PDT) Date: Fri, 5 Jul 2024 14:49:01 -0700 From: Larry McVoy To: John Levine Message-ID: <20240705214901.GR26356@mcvoy.com> References: <20240705213804.550128EDF53C@ary.qy> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240705213804.550128EDF53C@ary.qy> User-Agent: Mutt/1.5.24 (2015-08-30) Message-ID-Hash: OZUSUHZAR66IDUGLS2DSD4MPX7NBS6UO X-Message-ID-Hash: OZUSUHZAR66IDUGLS2DSD4MPX7NBS6UO X-MailFrom: lm@mcvoy.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: tuhs@tuhs.org, peter.martin.yardley@gmail.com X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: mental architecture models, Anyone ever heard of teaching a case study of Initial Unix? List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Fri, Jul 05, 2024 at 05:38:03PM -0400, John Levine wrote: > It appears that Peter Yardley said: > >The DG Nova had a pretty nice architecture. 2 accumulators, 2 index registers, program counter, status register. No stack register tho. There was a micro processor version by Fairchild. > > It did, but it was word addressed which makes it an historical > curiosity like its spiritual predecessors PDP-4/5/7/8/9. > > I also have a mental model of a PDP-11 but these days it's more a simplified 386 > leaving out the dumb or useless stuff. I took a look at x86 in 386/486 days and found it to be enough of a mess that I stopped looking. In no way did it compare the simplicity and elegance of the PDP-11. I had a TA, Ken Witte, who could read octal dumps of PDP-11 assembly like it was C. I'm pretty sure the way the instructions were encoded was a big part of what made that possible. -- --- Larry McVoy Retired to fishing http://www.mcvoy.com/lm/boat